Kansas City starting pitcher Brian Bannister, right, delivers a throw to Seattle's Adrian Beltre. Bannister allowed just four hits in his second career start, but took the loss Sunday in Seattle.

Seattle ? Cha Seung Baek made an impressive case for a spot in the Seattle Mariners’ rotation – even when Felix Hernandez returns from injury.

Manager Mike Hargrove isn’t letting on yet whether that will happen.

Baek overpowered Kansas City, carrying a no-hit bid into the sixth, and Willie Bloomquist’s second hit of the season was the difference in Seattle’s 5-1 win over the Royals on Sunday.

Seattle won for the fifth time in its last six, and Baek’s performance perpetuated the debate about Jeff Weaver’s future in the Mariners’ rotation.

Weaver, who is winless in four starts with an 18.26 ERA, was pulled after just one-third of an inning Saturday night, giving up six runs and seven hits. Hargrove knew the question was coming after Baek’s performance Sunday but wasn’t ready to make a pronouncement about his future rotation.

“That will work its way out. That’s a legitimate question, but again it’s not fair to anybody if I comment on that right now,” Hargrove said.

Baek pitched well in August and September last year, going 4-1 in six starts. He started this season in Triple-A, but was called up on April 23 when Hernandez went to the disabled list with a muscle strain in his right forearm. Baek threw 41â3 innings in his first start against Texas.

He dominated the Royals for six innings, and needed to as Seattle managed just four hits off Kansas City starter Brian Bannister (0-1). Mark Grudzielanek got the Royals’ first hit on a line drive single to center with two outs in the sixth.

When Baek tired in the seventh, rookie Brandon Morrow (2-0) entered and got a pair of strikeouts with runners on second and third. He then pitched a perfect eighth.

Morrow got the victory after Bloomquist took advantage of a second opportunity. Bloomquist fouled off a 3-2 pitch from Bannister and the ball got stuck behind catcher John Buck’s chest protector. Buck tried to jog off the field, claiming the inning was over. Home plate umpire Chris Guccione immediately called it a foul ball, but then listened as Buck and Royals manager Buddy Bell argued to reverse the decision.

Guccione conferred with the rest of the crew and his initial ruling stood. Rule 6.05b states the batter is not out if the ball lodges in the catcher’s equipment or clothing unless it hits his hand or glove first.

“First of all, they have to simplify the rule,” Bell said. “That play happens too fast for the home plate umpire; it happens too fast for the second base umpire. If he fouls off the ball and it doesn’t hit the ground, it should be a strikeout, plain and simple.”

Bloomquist then lined the next pitch into center field and David DeJesus’ diving attempt came up empty, as Jose Guillen and Yuniesky Betancourt scored.